Marine steam-generating unit



July24, 1928' 1,677;901

. J. J. NELIS MARINE STEAM GENERATING UNIT Filed May 10. 1925 2 Sheets-Sheet l INVENTOR A TTORNEY July 24, 1928 J. J. NELIS MARINE STEAM GENERATING UNIT Filed May 10, 1925 2 Sheets-Sheet INVENTOR 'A TTORNEY Patented July 24, I28,

rA'rEs v 1,677,901 PATENT OFFICE.

JOSEPH JOHN NELIS, OF BROOKLYN, NEW YQRK, ASSIGN'OR T0 FOSTER WHEELER GOR- POJRATION, OF NEW YORK, N Y.

Application filed May 10,

In carrying out my invention I combine a boiler of the inclined water tube cross drum type with an economizer above the, boiler tubes, and with'a superheater suitably 1I1COI- porated in the wall of the furnace chamber, and receiving its heat by radiation from the .furnace chamber. With this comb natlon I am enabled to obtain a desirably hlgh overall effipiency and improved furnace chamber conditions, and to prolong the l fe of the boiler furnace walls, with apparatus whlch, because of its compactness and structural characteristics, is well adapted for marine service. The economizer which I prefer to employ, while especially adapted for use in the above mentioned combinat on comprises novel features of general utility.

The various features: of novelty which characterize my invention are pointedout with particularity in the claims annexed to and-forming a part of this specificat on. For a better understanding of my invention, however, reference should be had to the accompanying drawings and descriptive mat= ter in: which I have illustrated and described preferred embodiments of my invention. v Of the drawings: 4

Fig. l is-an elevation in section;

Fig. 2 is a section on the.line 2-2 of Fig.1; 7

Fig. 3 is a partial section on the line of Fi-g. 1; and z Fig. ,4.- is a longitudinal section 7 tion of an economizertube. v

The boiler shown in the drawings comprises front and read headers A and A,

of a porconnected by a bank of straight water tubes. A The tubes A are inclined and the rea header A is higher than the front header.

A cross steam and water drum A is connected to the front header A by nipples A and is connected to the rear header A by circulating tubes -A"., which extend hori-f zontallv from the drum and have upwardly inclined portions adjacent the rear header A CORPORATION or NEW Yomn 5 run STEAM-GENERATING UNIT. 1

1923. Serial No. 637,997.

of steel, insure the proper distribution of flow and length of gas passage for the heating gases passing upward through the intertube-spaceof the boiler from the boiler furnace combustion chamber C. The boiler may be coal fired or oil fired. As shown it is heated by oil burners X mounted in the front wall of the combustion chamber.

Ihe superheater G which I employ, is incorporated in the combustion chamber wall at the rear of the chamber C immediately beneath the elevated rear header'A and is of .the type comprising a sectional metallic structure having its inner surface exposedv to the interior of the furnace chamber and receiving heat by radiation therefrom and conducting the heat so, absorbed to the steam flowing through channels in thestructure. In the construction illustrated, the steam flows through tubes g having vertical body portions and transverse end portions 9' which are connected to the superheater inlet header H and=outlet header HA. The vertical bodies of the tubes 9 are encased in,

cast iron-blocks g the smooth inner faces of which are exposed to the interior of the combustion chamber and absorb radiant heat from the burning gases in that chamber and from the side, bottom and front walls of the chamber. In some cases a row of socalled shadow bricks 9 may be interposed -.-as shown between adjacent pairs of superheater elements. The bricks 9 project into the furnace chamber past the inner faces of the blocks 9 and restrict the radiant heat absorption-of the latter somewhat. The super- 1' heater casing blocks 9 or some of them, are advantageously connected to a metallic framework G which serves to support the superheater and to preserve the alignment of the superheatertubes, and may also serve to carry a portion of thezweight of the boiler and boiler housing above the superheater. The side, bottom and front end walls of the furnace chamber are lined with fire brick D and the boiler and furnace housing is advantageously encased in a sheet metal sheathing F to prevent air leakage. A suitable insulating material E is preferably interposed between the fire-brick liningD and the sheathing and is also interposed between the superheater G and the adjacent portion of the sheathing. G is a superheater drain.

The economizer K, which is mounted above the water tubes comprises a bank of horizontally disposed tubes K which extend transversely to the water tubes and pass through a box-like casing K formed of metal plates and open at one end K to receive the heating gases from the boiler and open at itsopposite end K to pass the gases to the stack. The economizer tubes are ad- Vantageously formed, as shown in Fig. 4, of

steel tubes encased in tubular and eXterside the inlet end of the economizer K, and

is formed with an outlet for the heating gases communicating directly with the gas inlet K of the economizer. The economizer as shown is flattened, its horizontal dimensions parallel and transverse to the tubes K being each substantiallygreater than the vertical dimension of the economizer. The

economizer casing proper is covered with insulatlng material encased in a metal sheathng forming in eflect, an extension of the boiler housing sheathing F. r

The economizer tubes are closely spaced and arranged in vertical rows with the tubes in adjacent rows staggered. The tubes in the row adjacent the casing end K are each connected at one end tothe feed water inlet header L, and thetubes, in the row at the opposite end of the economizer are each con-- nected at one end to the outlet chamber LA from which the heated feed water passes to the drum A through the boiler feed pipe vM. The economizer tubes in each intermediate row are connected to the tubes in an adjacent row at one side of the economizer by headers or connectors L, and are connected at the other side of the economizer to the tubes of the other adjacent row by headers or connectors L tube sheet extending across the bankof tubes midway between the ends of the economizer.

Spray pipes O are located in the casing K above the bank of economizer tubes. \As shown these spray pipes areparallel to the economizer tubes and are spaced at regular intervals along the length of the economizer and each extends across the economizer casing. Each adjacent pair of pipes O are connected to a separate water supply pipe 0, so that the economizer may readily be cleanedin sections by successively supplying K represents a v q he /wet water to the different pairs of spray pipes. With economizer tubes of the character described and arranged in vertical rows as shown, the water flowing down over each upper tube falls on to the tube immediately beneath it, so that the wash water supplied to each section does not spread to other sec tions. By washing the economizer in sections undue cooling of the economizer as a whole is avoided, and less disturbance in the operation of the economizer is caused than would occur it the whole economizer was washed at the same time. The bottom of the, economizer casing is shaped to form a sort of a well beneath the bank of economizer tubes to receive the wash water which, 1

with the soot or other furnace dust washed off the tubes, may be removed from the economizer housing through the drain pipe connections P. The cleaning of the economizer tubes from time to-time, enables a high economizer efliciency to be maintained.

Spaces are provided in the economizer casing above and below the bank of tubes to receive the spray pipes O and permit the proper discharge of water therefrom onto the adjacent portions of the tube bank, and to receive the wash water dripping from the tubes. To prevent the heating gases from flowing through these spaces top and bottom bail'les Q and Q, respectively, are employed. These baffles are vertically disposed plates extending parallel to the economizer tubes. The top battles Q parallel and extending downward from the top wall of the economizer housing and the bottom baffles Q extend down toward, but not uite into contact with the bottom portion 0 the economizer casing. Advantageously' each' of these bafiles has its edge adjacent the bank of tubes extending into a corresponding one of the indentat1ons formed .in the top and bottom of the bank'as a result of thearrangement of the tubes in vertical rows with the tubes in adjacent rows staggered.

- The economizer construction disclosed, while especially devisedand adapted for use in the relation shown, is well adapted for use wherever it is desirable to have the heating gases flow horizontally through an economizer. The steam generating unit, as a wholeposses'ses important practical advantages for use under the severe conditions to which marine boilers are normally subjected. I The available spacefor such boilers is extremely restricted, and the ratio of steam generated per unit of volume of space oc- 1 cupied must be relatively high. The available head room, or vertical distance from top to bottom of the space available for the unit, is practically standard in most ships,

and substantiallv less than thatordiharily occupied by units of similar capacity in land service. In consequence it 1s a practically universal rule in marine boiler furnaces, to

provide less combustion chamber volume than is'provided in the fufnaces of land boilers of similar-capacity. Because of this decreased volume of combustion chamber space and the fact that the load on marine boilers is normally maintained approximately constant, and near the practical maximum capacity of the boilers throughout the time required 'fora ship to make a trip, marine boiler furnace walls tend to deteriorate more rapidly than do thecorresponding ,Walls of land boilers in which heavy load periods commonly alternate with light or no load periods. Marine boilers are ordinarily so. housed and operatedunder such draft, moreover, that their walls are not protected against overheating by the slow infiltration of air as is commonly the case with land boiler furnaces. v 7

With the present invention the entire rear wall of thecombustion chamber is directly .cooled by the superheater incorporated therein. In addition, the absorption of heat by the superheater, laowers the furnace chami her temperature, and cools the side, bottom and front end walls of the combustion chamber so that the superheaterprolongs the life of all portions'of the wall of the combustion chamber. In thearrangement disclosed, the superheater and the water tubes form radiant heat absorbing black bodies, which in a 'reducesjthe combustion chamber volume re quired for a given combustion capacity and efficiency. The invention also permits of a direct increase in combustion chamber volume by elongating the boiler, as compared with the practice heretofore standard, since with the radiant heat absorbed by the superheater. and the absorption of heat from the gases leaving the boiler by the economizer, the temperature of the gases leaving the economizer can be. kept sufficiently low with a bank of water tubes whichis relatively small in a vertical direction, and is increased horizontally to secure the required amount of boiler heating surface.

The type of economizer employed, by reason of its shape, and the character and close spacing of the economizer tubes, permits of an adequate amount of economizer heating surface in an economizer requiring a relatively small amount of head room. While the exact form and proportion of the parts,

and the size of the units are not essential features of the invention, it may facilitate a proper appreciation of the invention and its practical importance, to note the fact that a particular installation, of the form and relative proportions illustrated in the drawings, in which the total vertical distance from the bottom surface of the economize! casing is approximately sixteen and one half feet, was designed to, and is capable of generating steam economically and continuously at the rate of 16,000 lbs. per hour, at 250 lbs. pressure, and imparting 150 or more of superheat to the steam generated and can carry much heavier loads when occasion regquires. 3 While 31'1 accordance. with the provisions of the statutes, I have illustrated and described the best forms of my invention now known to me, it will be apparent to those skilled in the art that many changes may be made in the form of the apparatus disclosed without departing from the spirit of my invention as set forth in the appended claims, and that certain features of my 1n-- vention may sometimes be used with advantage without a corresponding use of other features.

Having now described myinvention, What I claim as new and desire to secure by'Lette'rs Patept, is:

1. A marine boiler comprising a combustion chamber, a bank of water tubes above said combustion'chamber, upper and lower.

headers connected to said tubes, a steam and water drum above said lower header and extending transversely to said tubes, tube connections between said drum and headers, a radiant heat superheater incorporated in a wall of said combustion chamber and adapted to absorb radiant heat from the other walls of said chamber and an economizer located above said water tubes and the tube connections between the upper header and drum. p

2.. A marine boiler comprising a combustion chamber, a bank of inclined water tubes above said combustion chamber, upper and lower headers connected to said tubes, a steam and water drum above said lower header and extending transversely of said tubes, tube connections between said drum and headers, a radiant superheater incor-.

porated in the high end wall of said combustion chamber and adapted to absorb radiant heat from the other wallsof" saidchamber and an economizer located above said water tubes and the tube connections between the upper header and drum. 1;..

tion chamber, a bank of inclined wa ter tubes above said combustion chamber, upper and lower headers connected to said; tubes, a steam and water drum above said lower 3. A marine boiler comprising a 'co mbusl- A i no Iii

closing said economizer tube bank having a heating gas inlet at one side and a heating gas outlet at the opposite side of said bank of tubes. v

4. The combination with a horizontal watertube boilercomprising upper and lower headers connected by the water tubes and a cross steam and water drum above the lower header, of an economizer located above thefwater tubes, and comprising a bank of. horizontal tubes transverse to the.

water tubes and a casing enclosing said bank and extending downward into the space be tween the higher header and said drum with an inlet for heating gases from the boiler at one side of the bank and an outlet for heating .gases at the other side of said bank.

5. The combination with a water tube boiler-,.comp rising upper and lower headers con' nected by the water tubes and a cross steam and water drum above the lower h(-3&L(l8I, Of an econoinizer above the water tubes and comprising a. bank of horizontal tubes transverse tothe water tubes and a casing enclosing said bank of tubes and extending down into the space between the higher heador and said drum, and a housing for the boiler comprising a portion extending upward alongside the economizer casing and com- I iiiunicating therewith through a port at one side of said bank of tubes.

6. An economizer comprising a bank of horizontal-tubes and a casing traversed by,

said tubes and provided with a heating gas inlet at one side, and a heating gas outlet at the opposite side of the tube bank, and spaced away'from the top and bottom of the bank means located in the space above the bank for discharging cleaning water onto the bank of tubes. drain connections from the space at the bottom of the bank, and baffles parallel to the water tubes in the spaces above and below the bank of water tubes restricting flow ot' the heating gases through said spaces.

7. An econoinizer comprising a bank of horizontal. tubes and a casing traversed by said tubes and provided with a heating gas inlet at one side, and a heating gas outlet at the opposite side of the bank and spaced away from the top and bottom of the bank, water spray pipes located in the space above the bank and extending parallel to the econ- I rec/7,905

above and below the bank of water tubes restricting flow of the heating gases through said spaces.

'8. An economizer comprising a bank of horizontal" tubes and cleaning means there-e for comprising spray pipes parallel to" said tubes arranged above said bank at horizontally spaced apart intervals, and separate water supply connections to said pipes whereby different sectionsof the bank may be washed at different times.

9. An economizer comprising a bank of horizontal tubes arranged in rows with the tubes in adjacent rows staggered whereby indentations are formed in the top surface of said bank, a casing enclosing said tubes and formed with a heating gas inlet at one side and a heating gas outlet at the opposite side the bank, baflies parallel to the tubes extendthe bank, and means located i'n the space above the tube bank for spraying wash water on to the tubes.

10. An ccononiizer comprising a bank of horizontal tubesarranged in rows with the tubes inadjacent rows staggered whereby indentations are formed in the top of said bank, a casing enclosing said tubes and formed with a heating gas inlet at one side of the bank and spaced away from the top of y "ing downward from the top of thejcasing into corresponding indentations in the top of anda heating gas outlet at the opposite side of the bank and spaced away from the top of thebank, bafiies parallel to the tubes ex tending downward from'thetop of the easing into corresponding indentations in the top of the bank, and means for spraying wash water on to the tubes comprising spray pipes parallel to said tubes and located in the spaceabove the tubes at the sides of said 11. An economizer comprising horizontal tubes arranged in staggered rows whereby indentations are formed at the bottom of the bank, a casing enclosing said bank and provided with a heating gas inlet at one side and a heating gas outlet at the a bank of opposite sideof the bank, and spaced away from the bottom of the bank to receive wash water draining oil? the tubes, means for spraying wash water on to the top of the bank of tubes, and bafiles parallel to the tubes and having their upper edges extending into corresponding indentations in the lower side of the'bank for restricting flow of the heating gases through said space.

Signed at New York city, in the county of New York and State of New York, this 8th day of May, A. D. 1923.

JOSEPH JOHN NELIS. 

